Analyses for ‘A Translational Paradigm to Study the Effects of Uncontrollable Stress in Humans’
Study 2 Analysis
Laura E. Meine (based on earlier code written by Laura E. Meine and Katja Schueler)
23.07.2020
1 Summary
This script runs analyses on data from study 2. Specifically, it compares data from two groups of participants who underwent escapable stress (EC) or yoked inescapable stress (YC), respectively. We use the terms “group” and “condition” interchangeably. . Measurements under investigation comprised reaction times (RTs) and ratings under acute stress (stressor aversiveness, control, exhaustion, helplessness) as well as pre-post changes in affective state (STADI and PANAS questionnaires), and effects escape behaviour (activity, exploration, escapes, efficiency).
2 Sample Descriptives
In total, the sample consisted of N = 100 participants with n = 62 in EC and n = 38 in YC.
2.1 Age & Sex
3 A priori Group Difference Checks
3.1 Sex (Chi-square Test)
##
## Pearson's Chi-squared test with Yates' continuity correction
##
## data: demo$condition and demo$sex
## X-squared = 0.061738, df = 1, p-value = 0.8038There were no a priori group differences in male-female ratio.
3.2 Age (t-test)
##
## Two Sample t-test
##
## data: demo$age[demo$condition == "EC"] and demo$age[demo$condition == "YC"]
## t = -1.758, df = 98, p-value = 0.08186
## alternative hypothesis: true difference in means is not equal to 0
## 95 percent confidence interval:
## -3.169705 0.191776
## sample estimates:
## mean of x mean of y
## 22.77419 24.26316##
## Cohen's d
##
## d estimate: -0.362193 (small)
## 95 percent confidence interval:
## lower upper
## -0.77418265 0.04979672Overall, there were no significant differences in age across groups (only a trend effect).There were two extreme outliers which we excluded from subsequent analyses.
3.3 Level of Education
## # A tibble: 1 x 8
## .y. group1 group2 n1 n2 statistic p p.signif
## <chr> <chr> <chr> <int> <int> <dbl> <dbl> <chr>
## 1 education_level EC YC 62 38 1102. 0.507 ns## # A tibble: 1 x 7
## .y. group1 group2 effsize n1 n2 magnitude
## * <chr> <chr> <chr> <dbl> <int> <int> <ord>
## 1 education_level EC YC 0.0669 62 38 smallThere were no a priori group differences with respect to level of education.
4 Manipulation Check
4.1 Verify Yoking of Stress Durations
##
## Two Sample t-test
##
## data: stress$stress_duration[stress$condition == "EC"] and stress$stress_duration[stress$condition == "YC"]
## t = 0.6079, df = 5878, p-value = 0.5433
## alternative hypothesis: true difference in means is not equal to 0
## 95 percent confidence interval:
## -0.0681606 0.1294337
## sample estimates:
## mean of x mean of y
## 7.896099 7.865463There were no overall differences in overall stress durations between EC and YC because YC participants were pseudoyoked to EC. Very slight timing inaccurracies are due to program execution differences. Note that durations across trials differ between groups. We deliberately introduced a discount of max. stress exposure in EC to enhance the feeling of control. In YC, we randomly shuffled stress durations obtained from EC to enhance the feeling of arbitrary stress durations outside the participant’s control.
4.2 Assess Performance in EC
8 EC participants had less than 30% correct trials, however, excluding them did not affect subsequent results, so we kept them.
4.3 Stressor Aversiveness
There were no extreme outliers with respect to aversiveness ratings.
##
## Univariate Type III Repeated-Measures ANOVA Assuming Sphericity
##
## Sum Sq num Df Error SS den Df F value Pr(>F)
## (Intercept) 10617.7 1 953.48 95 1057.9007 < 2e-16 ***
## condition 0.1 1 953.48 95 0.0071 0.93323
## trial 4.1 3 151.37 285 2.5876 0.05329 .
## condition:trial 0.4 3 151.37 285 0.2778 0.84138
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
##
## Mauchly Tests for Sphericity
##
## Test statistic p-value
## trial 0.61671 1.2643e-08
## condition:trial 0.61671 1.2643e-08
##
##
## Greenhouse-Geisser and Huynh-Feldt Corrections
## for Departure from Sphericity
##
## GG eps Pr(>F[GG])
## trial 0.74495 0.07123 .
## condition:trial 0.74495 0.78170
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## HF eps Pr(>F[HF])
## trial 0.7637362 0.06972818
## condition:trial 0.7637362 0.78698345## Anova Table (Type 3 tests)
##
## Response: aversive_rating
## Effect df MSE F pes p.value
## 1 condition 1, 95 10.04 0.01 <.0001 .93
## 2 trial 2.23, 212.31 0.71 2.59 + .03 .07
## 3 condition:trial 2.23, 212.31 0.71 0.28 .003 .78
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '+' 0.1 ' ' 1
##
## Sphericity correction method: GG##
## Univariate Type III Repeated-Measures ANOVA Assuming Sphericity
##
## Sum Sq num Df Error SS den Df F value Pr(>F)
## (Intercept) 10096.6 1 884.23 93 1061.9212 < 2.2e-16 ***
## condition 0.0 1 884.23 93 0.0034 0.953671
## sex 66.8 1 884.23 93 7.0295 0.009425 **
## condition:sex 0.3 1 884.23 93 0.0304 0.862051
## trial 3.1 3 143.42 279 1.9862 0.116250
## condition:trial 0.6 3 143.42 279 0.4075 0.747721
## sex:trial 3.8 3 143.42 279 2.4461 0.064159 .
## condition:sex:trial 5.9 3 143.42 279 3.8019 0.010699 *
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
##
## Mauchly Tests for Sphericity
##
## Test statistic p-value
## trial 0.65263 2.2291e-07
## condition:trial 0.65263 2.2291e-07
## sex:trial 0.65263 2.2291e-07
## condition:sex:trial 0.65263 2.2291e-07
##
##
## Greenhouse-Geisser and Huynh-Feldt Corrections
## for Departure from Sphericity
##
## GG eps Pr(>F[GG])
## trial 0.76818 0.13255
## condition:trial 0.76818 0.69478
## sex:trial 0.76818 0.08086 .
## condition:sex:trial 0.76818 0.01879 *
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## HF eps Pr(>F[HF])
## trial 0.7888231 0.13104078
## condition:trial 0.7888231 0.70015330
## sex:trial 0.7888231 0.07921093
## condition:sex:trial 0.7888231 0.01786286## Anova Table (Type 3 tests)
##
## Response: aversive_rating
## Effect df MSE F pes p.value
## 1 condition 1, 93 9.51 0.00 <.0001 .95
## 2 sex 1, 93 9.51 7.03 ** .07 .009
## 3 condition:sex 1, 93 9.51 0.03 .0003 .86
## 4 trial 2.30, 214.32 0.67 1.99 .02 .13
## 5 condition:trial 2.30, 214.32 0.67 0.41 .004 .69
## 6 sex:trial 2.30, 214.32 0.67 2.45 + .03 .08
## 7 condition:sex:trial 2.30, 214.32 0.67 3.80 * .04 .02
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '+' 0.1 ' ' 1
##
## Sphericity correction method: GG
Both EC and YC rated the stressor as very aversive (global M = 5.3814433). Mean aversiveness ratings did not differ between groups. Stressor aversiveness ratings remained constant over time (there was only a trend for change over trials). We observed a group x sex x trial interaction.
4.4 Perceived Stressor Controllability
There were no extreme outliers with respect to perceived control ratings.
##
## Univariate Type III Repeated-Measures ANOVA Assuming Sphericity
##
## Sum Sq num Df Error SS den Df F value Pr(>F)
## (Intercept) 2746.38 1 931.58 96 283.0182 < 2.2e-16 ***
## condition 157.49 1 931.58 96 16.2291 0.0001123 ***
## trial 31.74 3 454.55 288 6.7035 0.0002182 ***
## condition:trial 9.54 3 454.55 288 2.0140 0.1121045
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
##
## Mauchly Tests for Sphericity
##
## Test statistic p-value
## trial 0.75805 8.0297e-05
## condition:trial 0.75805 8.0297e-05
##
##
## Greenhouse-Geisser and Huynh-Feldt Corrections
## for Departure from Sphericity
##
## GG eps Pr(>F[GG])
## trial 0.84013 0.000554 ***
## condition:trial 0.84013 0.123273
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## HF eps Pr(>F[HF])
## trial 0.8646418 0.0004800631
## condition:trial 0.8646418 0.1215038746## Anova Table (Type 3 tests)
##
## Response: control_rating
## Effect df MSE F pes p.value
## 1 condition 1, 96 9.70 16.23 *** .14 .0001
## 2 trial 2.52, 241.96 1.88 6.70 *** .07 .0006
## 3 condition:trial 2.52, 241.96 1.88 2.01 .02 .12
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '+' 0.1 ' ' 1
##
## Sphericity correction method: GG## contrast estimate SE df t.ratio p.value
## X15 - X30 -0.35482 0.184 288 -1.927 0.1554
## X15 - X45 -0.35965 0.184 288 -1.953 0.1554
## X15 - X60 -0.82237 0.184 288 -4.465 0.0001
## X30 - X45 -0.00482 0.184 288 -0.026 0.9791
## X30 - X60 -0.46754 0.184 288 -2.539 0.0583
## X45 - X60 -0.46272 0.184 288 -2.512 0.0583
##
## Results are averaged over the levels of: condition
## P value adjustment: holm method for 6 tests## Call:
## bwtrim(formula = control_rating ~ condition * factor(trial),
## id = ID, data = ratings)
##
## value df1 df2 p.value
## condition 13.0942 1 53.9195 0.0007
## factor(trial) 3.7943 3 42.2487 0.0170
## condition:factor(trial) 3.4766 3 42.2487 0.0241##
## Univariate Type III Repeated-Measures ANOVA Assuming Sphericity
##
## Sum Sq num Df Error SS den Df F value Pr(>F)
## (Intercept) 2747.27 1 916.26 94 281.8458 < 2.2e-16 ***
## condition 150.27 1 916.26 94 15.4168 0.0001643 ***
## sex 15.10 1 916.26 94 1.5488 0.2164023
## condition:sex 0.20 1 916.26 94 0.0202 0.8873271
## trial 34.20 3 442.44 282 7.2653 0.0001037 ***
## condition:trial 8.06 3 442.44 282 1.7133 0.1644376
## sex:trial 2.58 3 442.44 282 0.5491 0.6491150
## condition:sex:trial 10.51 3 442.44 282 2.2330 0.0845811 .
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
##
## Mauchly Tests for Sphericity
##
## Test statistic p-value
## trial 0.76695 0.00016646
## condition:trial 0.76695 0.00016646
## sex:trial 0.76695 0.00016646
## condition:sex:trial 0.76695 0.00016646
##
##
## Greenhouse-Geisser and Huynh-Feldt Corrections
## for Departure from Sphericity
##
## GG eps Pr(>F[GG])
## trial 0.84524 0.0002837 ***
## condition:trial 0.84524 0.1732190
## sex:trial 0.84524 0.6196531
## condition:sex:trial 0.84524 0.0956516 .
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## HF eps Pr(>F[HF])
## trial 0.8706213 0.0002404004
## condition:trial 0.8706213 0.1717782978
## sex:trial 0.8706213 0.6248265690
## condition:sex:trial 0.8706213 0.0937452632## Anova Table (Type 3 tests)
##
## Response: control_rating
## Effect df MSE F pes p.value
## 1 condition 1, 94 9.75 15.42 *** .14 .0002
## 2 sex 1, 94 9.75 1.55 .02 .22
## 3 condition:sex 1, 94 9.75 0.02 .0002 .89
## 4 trial 2.54, 238.36 1.86 7.27 *** .07 .0003
## 5 condition:trial 2.54, 238.36 1.86 1.71 .02 .17
## 6 sex:trial 2.54, 238.36 1.86 0.55 .006 .62
## 7 condition:sex:trial 2.54, 238.36 1.86 2.23 + .02 .10
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '+' 0.1 ' ' 1
##
## Sphericity correction method: GGWe observed group differences in perceived control in the expected direction: YC reported lower control than EC. Overall perceived control increased over time (not clear why this would be the case in YC). No sex differences emerged.
5 Ratings and RT During Stress Exposure
5.1 Feelings of Helplessness
There were no outliers with respect to helplessness ratings.
##
## Two Sample t-test
##
## data: ratingMean$helpless_rating[ratingMean$condition == "EC"] and ratingMean$helpless_rating[ratingMean$condition == "YC"]
## t = -2.8957, df = 96, p-value = 0.004685
## alternative hypothesis: true difference in means is not equal to 0
## 95 percent confidence interval:
## -1.7379906 -0.3242901
## sample estimates:
## mean of x mean of y
## 4.133333 5.164474##
## Cohen's d
##
## d estimate: -0.6003342 (medium)
## 95 percent confidence interval:
## lower upper
## -1.0205757 -0.1800926
##
## Univariate Type III Repeated-Measures ANOVA Assuming Sphericity
##
## Sum Sq num Df Error SS den Df F value Pr(>F)
## (Intercept) 7820.1 1 1119.56 94 656.5840 < 2.2e-16 ***
## condition 97.3 1 1119.56 94 8.1654 0.005257 **
## sex 10.7 1 1119.56 94 0.8982 0.345687
## condition:sex 0.7 1 1119.56 94 0.0557 0.813939
## trial 51.1 3 521.53 282 9.2035 7.912e-06 ***
## condition:trial 2.1 3 521.53 282 0.3875 0.762110
## sex:trial 1.9 3 521.53 282 0.3378 0.798048
## condition:sex:trial 9.3 3 521.53 282 1.6675 0.174205
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
##
## Mauchly Tests for Sphericity
##
## Test statistic p-value
## trial 0.78507 0.00043271
## condition:trial 0.78507 0.00043271
## sex:trial 0.78507 0.00043271
## condition:sex:trial 0.78507 0.00043271
##
##
## Greenhouse-Geisser and Huynh-Feldt Corrections
## for Departure from Sphericity
##
## GG eps Pr(>F[GG])
## trial 0.87621 2.371e-05 ***
## condition:trial 0.87621 0.7355
## sex:trial 0.87621 0.7713
## condition:sex:trial 0.87621 0.1808
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## HF eps Pr(>F[HF])
## trial 0.9037063 1.857298e-05
## condition:trial 0.9037063 7.417994e-01
## sex:trial 0.9037063 7.776646e-01
## condition:sex:trial 0.9037063 1.793502e-01## Anova Table (Type 3 tests)
##
## Response: helpless_rating
## Effect df MSE F pes p.value
## 1 condition 1, 94 11.91 8.17 ** .08 .005
## 2 sex 1, 94 11.91 0.90 .009 .35
## 3 condition:sex 1, 94 11.91 0.06 .0006 .81
## 4 trial 2.63, 247.09 2.11 9.20 *** .09 <.0001
## 5 condition:trial 2.63, 247.09 2.11 0.39 .004 .74
## 6 sex:trial 2.63, 247.09 2.11 0.34 .004 .77
## 7 condition:sex:trial 2.63, 247.09 2.11 1.67 .02 .18
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '+' 0.1 ' ' 1
##
## Sphericity correction method: GG## contrast estimate SE df t.ratio p.value
## X15 - X30 0.758 0.201 282 3.764 0.0010
## X15 - X45 0.650 0.201 282 3.228 0.0056
## X15 - X60 1.015 0.201 282 5.042 <.0001
## X30 - X45 -0.108 0.201 282 -0.536 0.5926
## X30 - X60 0.257 0.201 282 1.278 0.4044
## X45 - X60 0.365 0.201 282 1.814 0.2122
##
## Results are averaged over the levels of: condition, sex
## P value adjustment: holm method for 6 tests## Call:
## bwtrim(formula = helpless_rating ~ condition * factor(trial),
## id = ID, data = ratings)
##
## value df1 df2 p.value
## condition 10.3935 1 64.2230 0.0020
## factor(trial) 5.1061 3 57.5366 0.0033
## condition:factor(trial) 1.1629 3 57.5366 0.3318As expected, YC reported greater feelings of helplessness compared to EC. Overall helplessness ratings decreased across trials.
5.2 Exhaustion
There were no outliers with respect to exhaustion ratings.
##
## Two Sample t-test
##
## data: ratingMean$exhausted_rating[ratingMean$condition == "EC"] and ratingMean$exhausted_rating[ratingMean$condition == "YC"]
## t = -1.6238, df = 96, p-value = 0.1077
## alternative hypothesis: true difference in means is not equal to 0
## 95 percent confidence interval:
## -1.3163883 0.1317391
## sample estimates:
## mean of x mean of y
## 4.420833 5.013158##
## Cohen's d
##
## d estimate: -0.3366555 (small)
## 95 percent confidence interval:
## lower upper
## -0.75094553 0.07763462
##
## Univariate Type III Repeated-Measures ANOVA Assuming Sphericity
##
## Sum Sq num Df Error SS den Df F value Pr(>F)
## (Intercept) 7856.9 1 1072.16 94 688.8370 < 2.2e-16 ***
## condition 21.8 1 1072.16 94 1.9148 0.1697074
## sex 107.6 1 1072.16 94 9.4337 0.0027862 **
## condition:sex 28.2 1 1072.16 94 2.4764 0.1189249
## trial 17.5 3 237.45 282 6.9456 0.0001589 ***
## condition:trial 2.3 3 237.45 282 0.9091 0.4369966
## sex:trial 5.0 3 237.45 282 1.9899 0.1156804
## condition:sex:trial 4.0 3 237.45 282 1.5877 0.1925216
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
##
## Mauchly Tests for Sphericity
##
## Test statistic p-value
## trial 0.61938 1.9125e-08
## condition:trial 0.61938 1.9125e-08
## sex:trial 0.61938 1.9125e-08
## condition:sex:trial 0.61938 1.9125e-08
##
##
## Greenhouse-Geisser and Huynh-Feldt Corrections
## for Departure from Sphericity
##
## GG eps Pr(>F[GG])
## trial 0.7679 0.0006584 ***
## condition:trial 0.7679 0.4162149
## sex:trial 0.7679 0.1320284
## condition:sex:trial 0.7679 0.2030627
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
##
## HF eps Pr(>F[HF])
## trial 0.7882936 0.0005807407
## condition:trial 0.7882936 0.4183250209
## sex:trial 0.7882936 0.1305292494
## condition:sex:trial 0.7882936 0.2021882118## Anova Table (Type 3 tests)
##
## Response: exhausted_rating
## Effect df MSE F pes p.value
## 1 condition 1, 94 11.41 1.91 .02 .17
## 2 sex 1, 94 11.41 9.43 ** .09 .003
## 3 condition:sex 1, 94 11.41 2.48 .03 .12
## 4 trial 2.30, 216.55 1.10 6.95 *** .07 .0007
## 5 condition:trial 2.30, 216.55 1.10 0.91 .010 .42
## 6 sex:trial 2.30, 216.55 1.10 1.99 .02 .13
## 7 condition:sex:trial 2.30, 216.55 1.10 1.59 .02 .20
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '+' 0.1 ' ' 1
##
## Sphericity correction method: GG## contrast estimate SE df t.ratio p.value
## X15 - X30 -0.416 0.136 282 -3.059 0.0122
## X15 - X45 -0.573 0.136 282 -4.218 0.0002
## X15 - X60 -0.179 0.136 282 -1.318 0.3771
## X30 - X45 -0.157 0.136 282 -1.159 0.3771
## X30 - X60 0.236 0.136 282 1.741 0.2483
## X45 - X60 0.394 0.136 282 2.900 0.0161
##
## Results are averaged over the levels of: condition, sex
## P value adjustment: holm method for 6 tests## Call:
## bwtrim(formula = exhausted_rating ~ condition * factor(trial),
## id = ID, data = ratings)
##
## value df1 df2 p.value
## condition 1.9115 1 69.8323 0.1712
## factor(trial) 7.3179 3 56.4622 0.0003
## condition:factor(trial) 0.8427 3 56.4622 0.4763There were no group differences in terms of exhaustion ratings. Overall reported exhaustion increased, then decreased over time. Men reported less exhaustion compared to women.
5.3 RTs
There were no extreme outliers with respect to RT.
##
## Two Sample t-test
##
## data: RTMean$rt[RTMean$condition == "EC"] and RTMean$rt[RTMean$condition == "YC"]
## t = -6.6664, df = 96, p-value = 1.659e-09
## alternative hypothesis: true difference in means is not equal to 0
## 95 percent confidence interval:
## -251.7004 -136.1993
## sample estimates:
## mean of x mean of y
## 652.8233 846.7731##
## Cohen's d
##
## d estimate: -1.382088 (large)
## 95 percent confidence interval:
## lower upper
## -1.8378929 -0.9262839
## Call:
## bwtrim(formula = rt ~ condition * trial, id = ID, data = stress)
##
## value df1 df2 p.value
## trial 0.9567 59 390.5510 0.5691
## condition 504.0623 1 948.6703 0.0000
## trial:condition 0.8877 59 390.6699 0.7069## [1] -0.8469792## [1] -0.247322##
## Two Sample t-test
##
## data: RTMean$rt[RTMean$sex == "f"] and RTMean$rt[RTMean$sex == "m"]
## t = 0.94389, df = 96, p-value = 0.3476
## alternative hypothesis: true difference in means is not equal to 0
## 95 percent confidence interval:
## -35.80524 100.72944
## sample estimates:
## mean of x mean of y
## 742.2719 709.8098EC was significantly faster than YC. There was no effect of trial.
6 Changes in Affective State
6.1 Depression and Anxiety (STADI)
There were no extreme outliers with respect to STADI scores.
##
## Univariate Type III Repeated-Measures ANOVA Assuming Sphericity
##
## Sum Sq num Df Error SS den Df F value Pr(>F)
## (Intercept) 238779 1 11199.5 96 2046.7743 < 2.2e-16 ***
## condition 361 1 11199.5 96 3.0948 0.081731 .
## time 158 1 1359.8 96 11.1309 0.001209 **
## condition:time 2 1 1359.8 96 0.1438 0.705393
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1## Anova Table (Type 3 tests)
##
## Response: STADI_S_Global
## Effect df MSE F pes p.value
## 1 condition 1, 96 116.66 3.09 + .03 .08
## 2 time 1, 96 14.17 11.13 ** .10 .001
## 3 condition:time 1, 96 14.17 0.14 .001 .71
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '+' 0.1 ' ' 1## Call:
## bwtrim(formula = STADI_S_Global ~ condition * factor(time), id = ID,
## data = affStates)
##
## value df1 df2 p.value
## condition 2.3817 1 58.5819 0.1281
## factor(time) 9.3493 1 67.2334 0.0032
## condition:factor(time) 0.1612 1 67.2334 0.6893##
## Univariate Type III Repeated-Measures ANOVA Assuming Sphericity
##
## Sum Sq num Df Error SS den Df F value Pr(>F)
## (Intercept) 233801 1 11161 94 1969.1849 < 2.2e-16 ***
## condition 368 1 11161 94 3.0993 0.081581 .
## sex 16 1 11161 94 0.1345 0.714682
## condition:sex 14 1 11161 94 0.1170 0.733098
## time 140 1 1333 94 9.8866 0.002229 **
## condition:time 4 1 1333 94 0.3084 0.579996
## sex:time 13 1 1333 94 0.9216 0.339513
## condition:sex:time 20 1 1333 94 1.3935 0.240789
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1## Anova Table (Type 3 tests)
##
## Response: STADI_S_Global
## Effect df MSE F pes p.value
## 1 condition 1, 94 118.73 3.10 + .03 .08
## 2 sex 1, 94 118.73 0.13 .001 .71
## 3 condition:sex 1, 94 118.73 0.12 .001 .73
## 4 time 1, 94 14.18 9.89 ** .10 .002
## 5 condition:time 1, 94 14.18 0.31 .003 .58
## 6 sex:time 1, 94 14.18 0.92 .010 .34
## 7 condition:sex:time 1, 94 14.18 1.39 .01 .24
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '+' 0.1 ' ' 1There was a trend effect of group with YC showing slightly higher scores than EC at pre and post. Although both groups reported an sig. increase in depressive symptoms and anxiety from pre to post stress induction, there was no interaction effect, i.e. no differential changes in STADI scores.
6.2 Negative and Positive Mood (PANAS)
6.2.1 Negative Mood
There was one extreme outlier with respect to negative mood which we excluded from this analysis.
##
## Univariate Type III Repeated-Measures ANOVA Assuming Sphericity
##
## Sum Sq num Df Error SS den Df F value Pr(>F)
## (Intercept) 36333 1 3308.3 96 1054.3131 < 2.2e-16 ***
## condition 245 1 3308.3 96 7.1020 0.009034 **
## time 38 1 409.3 96 8.8304 0.003744 **
## condition:time 0 1 409.3 96 0.0766 0.782582
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1## Anova Table (Type 3 tests)
##
## Response: PANAS_neg
## Effect df MSE F pes p.value
## 1 condition 1, 96 34.46 7.10 ** .07 .009
## 2 time 1, 96 4.26 8.83 ** .08 .004
## 3 condition:time 1, 96 4.26 0.08 .0008 .78
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '+' 0.1 ' ' 1## Call:
## bwtrim(formula = PANAS_neg ~ condition * factor(time), id = ID,
## data = affStates)
##
## value df1 df2 p.value
## condition 6.0149 1 55.7833 0.0173
## factor(time) 7.0439 1 67.2829 0.0099
## condition:factor(time) 0.0061 1 67.2829 0.9380##
## Univariate Type III Repeated-Measures ANOVA Assuming Sphericity
##
## Sum Sq num Df Error SS den Df F value Pr(>F)
## (Intercept) 35058 1 2633.52 93 1238.0414 < 2.2e-16 ***
## condition 344 1 2633.52 93 12.1622 0.0007466 ***
## sex 29 1 2633.52 93 1.0064 0.3183582
## condition:sex 61 1 2633.52 93 2.1650 0.1445565
## time 31 1 372.49 93 7.8330 0.0062369 **
## condition:time 2 1 372.49 93 0.5096 0.4771162
## sex:time 6 1 372.49 93 1.5188 0.2209025
## condition:sex:time 35 1 372.49 93 8.7413 0.0039426 **
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1## Anova Table (Type 3 tests)
##
## Response: PANAS_neg
## Effect df MSE F pes p.value
## 1 condition 1, 93 28.32 12.16 *** .12 .0007
## 2 sex 1, 93 28.32 1.01 .01 .32
## 3 condition:sex 1, 93 28.32 2.17 .02 .14
## 4 time 1, 93 4.01 7.83 ** .08 .006
## 5 condition:time 1, 93 4.01 0.51 .005 .48
## 6 sex:time 1, 93 4.01 1.52 .02 .22
## 7 condition:sex:time 1, 93 4.01 8.74 ** .09 .004
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '+' 0.1 ' ' 1
There were sig. group differences in negative mood with slightly higher overall scores in YC compared to EC. We observed an overall decrease from pre to post stress induction but no interaction of group x time. However, a significant interaction of group x sex x time emerged.
6.2.2 Positive Mood
There were no outliers with respect to positive mood scores.
##
## Univariate Type III Repeated-Measures ANOVA Assuming Sphericity
##
## Sum Sq num Df Error SS den Df F value Pr(>F)
## (Intercept) 139671 1 10597.6 96 1265.2232 < 2.2e-16 ***
## condition 9 1 10597.6 96 0.0837 0.7730
## time 551 1 2056.7 96 25.7194 1.922e-06 ***
## condition:time 7 1 2056.7 96 0.3047 0.5822
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1## Anova Table (Type 3 tests)
##
## Response: PANAS_pos
## Effect df MSE F pes p.value
## 1 condition 1, 96 110.39 0.08 .0009 .77
## 2 time 1, 96 21.42 25.72 *** .21 <.0001
## 3 condition:time 1, 96 21.42 0.30 .003 .58
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '+' 0.1 ' ' 1##
## Univariate Type III Repeated-Measures ANOVA Assuming Sphericity
##
## Sum Sq num Df Error SS den Df F value Pr(>F)
## (Intercept) 138585 1 10271.4 94 1268.2739 < 2.2e-16 ***
## condition 0 1 10271.4 94 0.0044 0.94709
## sex 177 1 10271.4 94 1.6199 0.20624
## condition:sex 224 1 10271.4 94 2.0495 0.15557
## time 480 1 1940.5 94 23.2489 5.467e-06 ***
## condition:time 5 1 1940.5 94 0.2463 0.62083
## sex:time 109 1 1940.5 94 5.2769 0.02383 *
## condition:sex:time 0 1 1940.5 94 0.0021 0.96360
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1## Anova Table (Type 3 tests)
##
## Response: PANAS_pos
## Effect df MSE F pes p.value
## 1 condition 1, 94 109.27 0.00 <.0001 .95
## 2 sex 1, 94 109.27 1.62 .02 .21
## 3 condition:sex 1, 94 109.27 2.05 .02 .16
## 4 time 1, 94 20.64 23.25 *** .20 <.0001
## 5 condition:time 1, 94 20.64 0.25 .003 .62
## 6 sex:time 1, 94 20.64 5.28 * .05 .02
## 7 condition:sex:time 1, 94 20.64 0.00 <.0001 .96
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '+' 0.1 ' ' 1
There were no group differences in positive mood but an overall decrease from pre to post stress induction. Men displayed a slightly smaller decrease compared to women.
7 Escape Behaviour
7.1 Activity (moves per minute)
There were two extreme outliers with respect to activity and we excluded them from this analysis.
##
## Univariate Type III Repeated-Measures ANOVA Assuming Sphericity
##
## Sum Sq num Df Error SS den Df F value Pr(>F)
## (Intercept) 9984411 1 1791802 96 534.9383 < 2.2e-16 ***
## condition 10299 1 1791802 96 0.5518 0.4594
## phase 594560 1 696970 96 81.8941 1.638e-14 ***
## condition:phase 7117 1 696970 96 0.9803 0.3246
## block 191098 1 381050 96 48.1444 4.635e-10 ***
## condition:block 10263 1 381050 96 2.5857 0.1111
## phase:block 533 1 122017 96 0.4193 0.5188
## condition:phase:block 130 1 122017 96 0.1020 0.7501
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1## Anova Table (Type 3 tests)
##
## Response: mpm
## Effect df MSE F pes p.value
## 1 condition 1, 96 18664.60 0.55 .006 .46
## 2 phase 1, 96 7260.11 81.89 *** .46 <.0001
## 3 condition:phase 1, 96 7260.11 0.98 .01 .32
## 4 block 1, 96 3969.27 48.14 *** .33 <.0001
## 5 condition:block 1, 96 3969.27 2.59 .03 .11
## 6 phase:block 1, 96 1271.01 0.42 .004 .52
## 7 condition:phase:block 1, 96 1271.01 0.10 .001 .75
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '+' 0.1 ' ' 1##
## Univariate Type III Repeated-Measures ANOVA Assuming Sphericity
##
## Sum Sq num Df Error SS den Df F value Pr(>F)
## (Intercept) 10107465 1 1584770 94 599.5201 < 2.2e-16
## condition 9917 1 1584770 94 0.5882 0.445034
## sex 167354 1 1584770 94 9.9265 0.002185
## condition:sex 9799 1 1584770 94 0.5812 0.447742
## phase 599596 1 675452 94 83.4434 1.271e-14
## condition:phase 5796 1 675452 94 0.8067 0.371406
## sex:phase 10188 1 675452 94 1.4178 0.236761
## condition:sex:phase 6426 1 675452 94 0.8943 0.346750
## block 199684 1 367752 94 51.0407 1.906e-10
## condition:block 13213 1 367752 94 3.3773 0.069260
## sex:block 7561 1 367752 94 1.9326 0.167758
## condition:sex:block 8804 1 367752 94 2.2504 0.136928
## phase:block 385 1 119991 94 0.3018 0.584083
## condition:phase:block 26 1 119991 94 0.0201 0.887461
## sex:phase:block 227 1 119991 94 0.1775 0.674534
## condition:sex:phase:block 2003 1 119991 94 1.5690 0.213454
##
## (Intercept) ***
## condition
## sex **
## condition:sex
## phase ***
## condition:phase
## sex:phase
## condition:sex:phase
## block ***
## condition:block .
## sex:block
## condition:sex:block
## phase:block
## condition:phase:block
## sex:phase:block
## condition:sex:phase:block
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1## Anova Table (Type 3 tests)
##
## Response: mpm
## Effect df MSE F pes p.value
## 1 condition 1, 94 16859.26 0.59 .006 .45
## 2 sex 1, 94 16859.26 9.93 ** .10 .002
## 3 condition:sex 1, 94 16859.26 0.58 .006 .45
## 4 phase 1, 94 7185.66 83.44 *** .47 <.0001
## 5 condition:phase 1, 94 7185.66 0.81 .009 .37
## 6 sex:phase 1, 94 7185.66 1.42 .01 .24
## 7 condition:sex:phase 1, 94 7185.66 0.89 .009 .35
## 8 block 1, 94 3912.25 51.04 *** .35 <.0001
## 9 condition:block 1, 94 3912.25 3.38 + .03 .07
## 10 sex:block 1, 94 3912.25 1.93 .02 .17
## 11 condition:sex:block 1, 94 3912.25 2.25 .02 .14
## 12 phase:block 1, 94 1276.50 0.30 .003 .58
## 13 condition:phase:block 1, 94 1276.50 0.02 .0002 .89
## 14 sex:phase:block 1, 94 1276.50 0.18 .002 .67
## 15 condition:sex:phase:block 1, 94 1276.50 1.57 .02 .21
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '+' 0.1 ' ' 1
There was no main effect of group but a significant difference in activity between the free exploration phase and the stress phase as well as between blocks. Participants showed increased activity over blocks and generally lower activity in the stress phase. Men showed more activity compared to women.
7.2 Exploration
There were no extreme outliers with respect to exploration.
##
## Univariate Type III Repeated-Measures ANOVA Assuming Sphericity
##
## Sum Sq num Df Error SS den Df F value Pr(>F)
## (Intercept) 5731290 1 1006749 96 546.5152 < 2.2e-16 ***
## condition 7727 1 1006749 96 0.7368 0.3928
## block 102147 1 201836 96 48.5848 3.993e-10 ***
## condition:block 1472 1 201836 96 0.7003 0.4048
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1## Anova Table (Type 3 tests)
##
## Response: exploration
## Effect df MSE F pes p.value
## 1 condition 1, 96 10486.97 0.74 .008 .39
## 2 block 1, 96 2102.46 48.58 *** .34 <.0001
## 3 condition:block 1, 96 2102.46 0.70 .007 .40
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '+' 0.1 ' ' 1## Call:
## bwtrim(formula = exploration ~ condition * factor(block), id = ID,
## data = explorationNoStress)
##
## value df1 df2 p.value
## factor(block) 53.0621 1 547.0090 0.0000
## condition 5.6131 1 500.5521 0.0182
## factor(block):condition 0.1403 1 500.5521 0.7082
##
## Univariate Type III Repeated-Measures ANOVA Assuming Sphericity
##
## Sum Sq num Df Error SS den Df F value Pr(>F)
## (Intercept) 5809501 1 893765 94 611.0027 < 2.2e-16 ***
## condition 8237 1 893765 94 0.8663 0.35438
## sex 99044 1 893765 94 10.4167 0.00172 **
## condition:sex 1759 1 893765 94 0.1850 0.66811
## block 109881 1 189453 94 54.5189 6.132e-11 ***
## condition:block 2496 1 189453 94 1.2383 0.26864
## sex:block 10051 1 189453 94 4.9869 0.02791 *
## condition:sex:block 4929 1 189453 94 2.4454 0.12123
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1## Anova Table (Type 3 tests)
##
## Response: exploration
## Effect df MSE F pes p.value
## 1 condition 1, 94 9508.14 0.87 .009 .35
## 2 sex 1, 94 9508.14 10.42 ** .10 .002
## 3 condition:sex 1, 94 9508.14 0.18 .002 .67
## 4 block 1, 94 2015.46 54.52 *** .37 <.0001
## 5 condition:block 1, 94 2015.46 1.24 .01 .27
## 6 sex:block 1, 94 2015.46 4.99 * .05 .03
## 7 condition:sex:block 1, 94 2015.46 2.45 .03 .12
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '+' 0.1 ' ' 1
There was no main effect of group but a significant difference in exploration between blocks. Participants showed increased exploration in block 2. In block 2, men explored more compared to women.
7.3 Escapes
There were no outliers with respect to escape rate.
##
## Univariate Type III Repeated-Measures ANOVA Assuming Sphericity
##
## Sum Sq num Df Error SS den Df F value Pr(>F)
## (Intercept) 805.27 1 406.73 96 190.0698 < 2e-16 ***
## condition 0.27 1 406.73 96 0.0647 0.79976
## block 10.65 1 222.98 96 4.5870 0.03475 *
## condition:block 11.86 1 222.98 96 5.1054 0.02611 *
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1## Anova Table (Type 3 tests)
##
## Response: sum_escapes_block
## Effect df MSE F pes p.value
## 1 condition 1, 96 4.24 0.06 .0007 .80
## 2 block 1, 96 2.32 4.59 * .05 .03
## 3 condition:block 1, 96 2.32 5.11 * .05 .03
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '+' 0.1 ' ' 1## contrast estimate SE df t.ratio p.value
## EC,X1 - YC,X1 -0.5816 0.375 177 -1.549 0.6159
## EC,X1 - EC,X2 -0.9833 0.278 96 -3.534 0.0038
## EC,X1 - YC,X2 -0.5553 0.375 177 -1.479 0.6159
## YC,X1 - EC,X2 -0.4018 0.375 177 -1.070 0.7673
## YC,X1 - YC,X2 0.0263 0.350 96 0.075 0.9402
## EC,X2 - YC,X2 0.4281 0.375 177 1.140 0.7673
##
## P value adjustment: holm method for 6 tests## Call:
## bwtrim(formula = sum_escapes_block ~ condition * factor(block),
## id = ID, data = escapesStress)
##
## value df1 df2 p.value
## condition 0.0742 1 62.5449 0.7862
## factor(block) 4.1194 1 65.1321 0.0465
## condition:factor(block) 7.2058 1 65.1321 0.0092##
## Univariate Type III Repeated-Measures ANOVA Assuming Sphericity
##
## Sum Sq num Df Error SS den Df F value Pr(>F)
## (Intercept) 813.69 1 395.78 94 193.2549 < 2e-16 ***
## condition 0.39 1 395.78 94 0.0935 0.76050
## sex 10.52 1 395.78 94 2.4980 0.11735
## condition:sex 0.01 1 395.78 94 0.0032 0.95523
## block 13.04 1 215.18 94 5.6970 0.01900 *
## condition:block 10.54 1 215.18 94 4.6046 0.03446 *
## sex:block 7.80 1 215.18 94 3.4063 0.06809 .
## condition:sex:block 0.41 1 215.18 94 0.1806 0.67185
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1## Anova Table (Type 3 tests)
##
## Response: sum_escapes_block
## Effect df MSE F pes p.value
## 1 condition 1, 94 4.21 0.09 .0010 .76
## 2 sex 1, 94 4.21 2.50 .03 .12
## 3 condition:sex 1, 94 4.21 0.00 <.0001 .96
## 4 block 1, 94 2.29 5.70 * .06 .02
## 5 condition:block 1, 94 2.29 4.60 * .05 .03
## 6 sex:block 1, 94 2.29 3.41 + .03 .07
## 7 condition:sex:block 1, 94 2.29 0.18 .002 .67
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '+' 0.1 ' ' 1
EC managed to escape more often in block 2 compared to block 1, whereas YC did not improve (scores denote rather a slight decrease!). However, this interaction was not significant upon correction of family-wise error. Men improved more than women from block 1 to block 2.
7.4 Efficiency
There were some outliers with respect to efficiency but excluding them did not affect the results, so we kept them.
##
## Univariate Type III Repeated-Measures ANOVA Assuming Sphericity
##
## Sum Sq num Df Error SS den Df F value Pr(>F)
## (Intercept) 1527186 1 405177 91 342.9955 < 2.2e-16 ***
## condition 8317 1 405177 91 1.8678 0.1750899
## block 10321 1 300281 91 3.1277 0.0803247 .
## condition:block 40854 1 300281 91 12.3809 0.0006793 ***
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1## Anova Table (Type 3 tests)
##
## Response: overall_efficiency
## Effect df MSE F pes p.value
## 1 condition 1, 91 4452.49 1.87 .02 .18
## 2 block 1, 91 3299.79 3.13 + .03 .08
## 3 condition:block 1, 91 3299.79 12.38 *** .12 .0007
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '+' 0.1 ' ' 1## contrast estimate SE df t.ratio p.value
## EC,X1 - YC,X1 16.62 13.2 178 1.260 0.5062
## EC,X1 - EC,X2 15.06 10.9 91 1.387 0.5062
## EC,X1 - YC,X2 -28.88 13.2 178 -2.190 0.1194
## YC,X1 - EC,X2 -1.56 13.2 178 -0.118 0.9061
## YC,X1 - YC,X2 -45.50 13.4 91 -3.407 0.0059
## EC,X2 - YC,X2 -43.94 13.2 178 -3.331 0.0059
##
## P value adjustment: holm method for 6 tests## Call:
## bwtrim(formula = overall_efficiency ~ condition * factor(block),
## id = ID, data = efficiencyStress)
##
## value df1 df2 p.value
## factor(block) 1.5804 1 33.3288 0.2174
## condition 0.8718 1 39.9654 0.3561
## factor(block):condition 5.9951 1 39.9654 0.0188##
## Univariate Type III Repeated-Measures ANOVA Assuming Sphericity
##
## Sum Sq num Df Error SS den Df F value Pr(>F)
## (Intercept) 1505474 1 399940 89 335.0181 < 2e-16 ***
## condition 7407 1 399940 89 1.6483 0.20252
## sex 335 1 399940 89 0.0745 0.78546
## condition:sex 4163 1 399940 89 0.9265 0.33838
## block 7606 1 281819 89 2.4019 0.12473
## condition:block 36227 1 281819 89 11.4407 0.00107 **
## sex:block 18150 1 281819 89 5.7318 0.01876 *
## condition:sex:block 2107 1 281819 89 0.6654 0.41684
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1## Anova Table (Type 3 tests)
##
## Response: overall_efficiency
## Effect df MSE F pes p.value
## 1 condition 1, 89 4493.71 1.65 .02 .20
## 2 sex 1, 89 4493.71 0.07 .0008 .79
## 3 condition:sex 1, 89 4493.71 0.93 .01 .34
## 4 block 1, 89 3166.50 2.40 .03 .12
## 5 condition:block 1, 89 3166.50 11.44 ** .11 .001
## 6 sex:block 1, 89 3166.50 5.73 * .06 .02
## 7 condition:sex:block 1, 89 3166.50 0.67 .007 .42
## ---
## Signif. codes: 0 '***' 0.001 '**' 0.01 '*' 0.05 '+' 0.1 ' ' 1
Whereas EC and YC did not differ in efficiency in block 1 (although YC had slightly better scores), YC showed sig. less efficient behaviour in block 2 compared to EC. There was also an interaction of sex x block.
8 Correction for Multiple Dependent Variables
8.1 Acute Stress Effects
## DVacute p.orig Bonferroni
## 3 RT 1.659e-09 4.9770e-09
## 1 helplessness 4.685e-03 1.4055e-02
## 2 exhaustion 1.077e-01 3.2310e-018.2 Transfer Stress Effects
## DVtransfer p.orig Bonferroni
## 6 efficiency 0.0006793 0.0040758
## 5 escapes 0.0261100 0.1566600
## 4 exploration 0.4048000 1.0000000
## 3 PANASpos 0.5822000 1.0000000
## 1 STADI 0.7053930 1.0000000
## 2 PANASneg 0.7825820 1.00000009 Plots for Paper
9.1 Figure 1
9.2 Figure 2
10 Plots for Supplement
